We'll have to agree to disagree on this one. Personally, I find the natural light easiest and most rewarding to achieve with actual natural light. ;) One important difference is the direction of the light. Unless you have an assistant running around holding the flash for you, you light is going to come from very close to your camera. Even if you hand hold the flash, you can't get it further away from you than arm's length. That's a big difference right there.
I was just asking and I will keep putting money in the bank, as I said, if you know how to use your flash, the natural light look is quite easy to achieve.